4310results about "From frozen solutions" patented technology

A bulk-doped semiconductor that is at least one of the following: a single crystal, an elongated and bulk-doped semiconductor that, at any point along its longitudinal axis, has a largest cross-sectional dimension less than 500 nanometers, and a free-standing and bulk-doped semiconductor with at least one portion having a smallest width of less than 500 nanometers. Such a semiconductor may comprise an interior core comprising a first semiconductor; and an exterior shell comprising a different material than the first semiconductor. Such a semiconductor may be elongated and my have, at any point along a longitudinal section of such a semiconductor, a ratio of the length of the section to a longest width is greater than 4:1, or greater than 10:1, or greater than 100:1, or even greater than 1000:1. At least one portion of such a semiconductor may a smallest width of less than 200 nanometers, or less than 150 nanometers, or less than 100 nanometers, or less than 80 nanometers, or less than 70 nanometers, or less than 60 nanometers, or less than 40 nanometers, or less than 20 nanometers, or less than 10 nanometers, or even less than 5 nanometers. Such a semiconductor may be a single crystal and may be free-standing. Such a semiconductor may be either lightly n-doped, heavily n-doped, lightly p-doped or heavily p-doped. Such a semiconductor may be doped during growth. Such a semiconductor may be part of a device, which may include any of a variety of devices and combinations thereof, and, and a variety of assembling techniques may be used to fabricate devices from such a semiconductor. Two or more of such a semiconductors, including an array of such semiconductors, may be combined to form devices, for example, to form a crossed p-n junction of a device. Such devices at certain sizes may exhibit quantum confinement and other quantum phenomena, and the wavelength of light emitted from one or more of such semiconductors may be controlled by selecting a width of such semiconductors. Such semiconductors and device made therefrom may be used for a variety of applications.

Apparatus and method for forming a polycrystalline silicon thin film by converting an amorphous silicon thin film into the polycrystalline silicon thin film using a metal are provided. The method includes: a metal nucleus adsorbing step of introducing a vapor phase metal compound into a process space where the glass substrate having the amorphous silicon formed thereon is disposed, to adsorb a metal nucleus contained in the metal compound into the amorphous silicon layer; a metal nucleus distribution region-forming step of forming a community region including a plurality of silicon particles every metal nucleus in a plane boundary region occupied by the metal compound by a self-limited mechanism due to the adsorption of the metal nucleus; and an excess gas removing step of purging and removing an excess gas which is not adsorbed in the metal nucleus distribution region-forming step.

A method for producing a nitride semiconductor, comprising controlling temperature and pressure in a autoclave containing a seed having a hexagonal crystal structure, a nitrogen element-containing solvent, a raw material substance containing a metal element of Group 13 of the Periodic Table, and a mineralizer so as to put said solvent into a supercritical state and / or a subcritical state and thereby ammonothermally grow a nitride semiconductor crystal on the surface of said seed, wherein the crystal growth rate in the m-axis direction on said seed is 1.5 times or more the crystal growth rate in the c-axis direction on said seed. By the method, a nitride semiconductor having a large-diameter C plane or a nitride semiconductor thick in the m-axis direction can be efficiently and simply produced.

The present invention provides methods, systems and system components for transferring, assembling and integrating features and arrays of features having selected nanosized and / or microsized physical dimensions, shapes and spatial orientations. Methods of the present invention utilize principles of ‘soft adhesion’ to guide the transfer, assembly and / or integration of features, such as printable semiconductor elements or other components of electronic devices. Methods of the present invention are useful for transferring features from a donor substrate to the transfer surface of an elastomeric transfer device and, optionally, from the transfer surface of an elastomeric transfer device to the receiving surface of a receiving substrate. The present methods and systems provide highly efficient, registered transfer of features and arrays of features, such as printable semiconductor element, in a concerted manner that maintains the relative spatial orientations of transferred features.

An improved capsule for processing materials or growing crystals in supercritical fluids. The capsule is scalable up to very large volumes and is cost effective according to a preferred embodiment. In conjunction with suitable high pressure apparatus, the capsule is capable of processing materials at pressures and temperatures of 0.2-8 GPa and 400-1500° C., respectively. Of course, there can be other variations, modifications, and alternatives.

A resonant tunneling diode, and other one dimensional electronic, photonic structures, and electromechanical MEMS devices, are formed as a heterostructure in a nanowhisker by forming length segments of the whisker with different materials having different band gaps.

A high pressure apparatus and related methods for processing supercritical fluids. In a specific embodiment, the present apparatus includes a capsule, a heater, at least one ceramic ring but can be multiple rings, optionally, with one or more scribe marks and / or cracks present. In a specific embodiment, the apparatus optionally has a metal sleeve containing each ceramic ring. The apparatus also has a high-strength enclosure, end flanges with associated insulation, and a power control system. In a specific embodiment, the apparatus is capable of accessing pressures and temperatures of 0.2-2 GPa and 400-1200° C., respectively.

A method for locally controlling the stoichiometry of an epitaxially deposited layer on a semiconductor substrate is provided. The method includes directing a first reactant gas and a doping gas across a top surface of a semiconductor substrate and directing a drive gas and a second reactant gas against the substrate separately from the first reactant gas in a manner that rotates the substrate while introducing the second reactant gas at an edge of the substrate to control each reactant separately, thereby compensating and controlling depletion effects and improving doping uniformity in resulting epitaxial layers on the substrate.

A method which can control crystallization of a biopolymer such as protein is provided. A silicon crystal (15) whose valence electrons are controlled to be capable of controlling the concentration of holes or electrons of the surface part in response to the environment of a buffer solution (14) containing the biopolymer such as protein is brought into contact with the solution (14), for getting a crystal of the biopolymer deposited on the surface of the silicon crystal (15). Crystallization is controlled by an electrical state which is generated by the controlled valence electrons on the surface of the silicon crystal (15).

A silicon production reactor comprising a reaction vessel and heating means, said reaction vessel comprising a vertically extending wall and a space surrounded by the wall, said heating means being capable of heating at least a part, including lower end portion, of the wall's surface facing the space to a temperature of not lower than the melting point of silicon, said silicon production reactor being adapted to flow raw gas for silicon deposition from an upper part of the space of the reaction vessel toward a lower part thereof, characterized in that the space of the reaction vessel is of slit form in cross-sectional view. This silicon production reactor is capable of attaining improvement with respect to problems encountered at apparatus scaleup, such as decrease of reactivity of raw gas and generation of by-products, thereby accomplishing a striking enhancement of production efficiency.

The present invention is directed to methods to harvest, integrate and exploit nanomaterials, and particularly elongated nanowire materials. The invention provides methods for harvesting nanowires that include selectively etching a sacrificial layer placed on a nanowire growth substrate to remove nanowires. The invention also provides methods for integrating nanowires into electronic devices that include placing an outer surface of a cylinder in contact with a fluid suspension of nanowires and rolling the nanowire coated cylinder to deposit nanowires onto a surface. Methods are also provided to deposit nanowires using an ink-jet printer or an aperture to align nanowires. Additional aspects of the invention provide methods for preventing gate shorts in nanowire based transistors. Additional methods for harvesting and integrating nanowires are provided.

Large gas turbine blades made from separate cast segments of superalloys are disclosed. The turbine blade is designed such that bond lines between adjacent segments are placed in low stress regions of the blade. The cast superalloy segments of the blades are aligned and fitted together with specified tolerances. The turbine blade segments are then joined by transient liquid phase bonding, followed by a controlled heat treatment which produces the desired microstructure in the bond region. The method allows for the production of large, high quality turbine blades by joining small, high quality cast superalloy sections, in comparison with prior attempts to cast large turbine blades as single pieces which have produced very low yields and high individual component costs.

An apparatus and method for processing materials in supercritical fluids is disclosed. The apparatus includes a capsule configured to contain a supercritical fluid, a high strength enclosure disposed about the capsule and a sensor configured to sense pressure difference between an interior and an exterior of the capsule. The apparatus also includes a pressure control device configured to adjust pressure difference of the capsule in response to the pressure difference sensed by the sensor. The apparatus further includes at least one dividing structure disposed within the capsule that divides the capsule into a seed growing chamber and a nutrient chamber.

The present invention relates generally to sub-microelectronic circuitry, and more particularly to nanometer-scale articles, including nanoscale wires which can be selectively doped at various locations and at various levels. In some cases, the articles may be single crystals. The nanoscale wires can be doped, for example, differentially along their length, or radially, and either in terms of identity of dopant, concentration of dopant, or both. This may be used to provide both n-type and p-type conductivity in a single item, or in different items in close proximity to each other, such as in a crossbar array. The fabrication and growth of such articles is described, and the arrangement of such articles to fabricate electronic, optoelectronic, or spintronic devices and components. For example, semiconductor materials can be doped to form n-type and p-type semiconductor regions for making a variety of devices such as field effect transistors, bipolar transistors, complementary inverters, tunnel diodes, light emitting diodes, sensors, and the like.

A nanoengineered structure comprising an array of more than about 1000 nanowhiskers on a substrate in a predetermined spatial configuration, for use for example as a photonic band gap array, wherein each nanowhisker is sited within a distance from a predetermined site not greater than about 20% of its distance from its nearest neighbour. To produce the array, an array of masses of a catalytic material are positioned on the surface, heat is applied and materials in gaseous form are introduced such as to create a catalytic seed particle from each mass, and to grow, from the catalytic seed particle, epitaxially, a nanowhisker of a predetermined material, and wherein each mass upon melting, retains approximately the same interface with the substrate surface such that forces causing the mass to migrate across said surface are less than a holding force across a wetted interface on the substrate surface.

A method of method of forming or repairing a superalloy article having a columnar or equiaxed or directionally solidified or amorphous or single crystal microstructure includes emitting a plurality of laser beams from selected fibers of a diode laser fiber array corresponding to a pattern of a layer of the article onto a powder bed of the superalloy to form a melt pool; and controlling a temperature gradient and a solidification velocity of the melt pool to form the columnar or single crystal microstructure.

A substrate processing apparatus is used for radiating UV rays onto a target film formed on a target surface of a substrate to perform a curing process of the target film. The apparatus includes a hot plate configured to heat the substrate to a predetermined temperature, a plurality of support pins disposed on the hot plate to support the substrate, and a UV radiating device configured to radiate UV rays onto the target surface of the substrate supported on the support pins. The support pins are preset to provide a predetermined thermal conductivity to conduct heat of the substrate to the hot plate. The hot plate is preset to have a predetermined thermal capacity sufficient to absorb heat conducted through the support pins.

A method of forming a nanostructure having the form of a tree, comprises a first stage and a second stage. The first stage includes providing one or more catalytic particles on a substrate surface, and growing a first nanowhisker via each catalytic particle. The second stage includes providing, on the periphery of each first nanowhisker, one or more second catalytic particles, and growing, from each second catalytic particle, a second nanowhisker extending transversely from the periphery of the respective first nanowhisker. Further stages may be included to grow one or more further nanowhiskers extending from the nanowhisker(s) of the preceding stage. Heterostructures may be created within the nanowhiskers. Such nanostructures may form the components of a solar cell array or a light emitting flat panel, where the nanowhiskers are formed of a photosensitive material. A neural network may be formed by positioning the first nanowhiskers close together so that adjacent trees contact one another through nanowhiskers grown in a subsequent stage, and heterojunctions within the nanowhiskers create tunnel barriers to current flow.

The invention is related to nuclear physics, medicine and oil industry, namely to the measurement of x-ray, gamma and alpha radiation; control for trans uranium nuclides in the habitat of a man; non destructive control for the structure of heavy bodies; three dimensional positron-electron computer tomography, etc.The essence of the invention is in additional ingredients in a chemical composition of a scintillating material based on crystals of oxyorthosilicates, including cerium Ce and crystallized in a structural type Lu2SiO5.The result of the invention is the increase of the light output of the luminescence, decrease of the time of luminescence of the ions Ce3+, increase of the reproducibility of grown crystals properties, decrease of the cost of the source melting stock for growing scintillator crystals, containing a large amount of Lu2O3, the raise of the effectiveness of the introduction of SCintillating crystal luminescent radiation into a glass waveguide fibre, prevention of cracking of crystals during the production of elements, creation of waveguide properties in scintillating elements, exclusion of expensive mechanical polishing of their lateral surface.

In one embodiment, a method of fabricating a semiconductor device having a crystalline semiconductor layer includes preparing a semiconductor substrate and forming a preliminary active pattern on the semiconductor substrate. The preliminary active pattern includes a barrier pattern and a non-single crystal semiconductor pattern. A sacrificial non-single crystal semiconductor layer covers the preliminary active pattern and the semiconductor substrate. By crystallizing the sacrificial non-single crystal semiconductor layer and the non-single crystal semiconductor pattern, using the semiconductor substrate as a seed layer, the sacrificial non-single crystal semiconductor layer and the non-single crystal semiconductor pattern are changed to a sacrificial crystalline semiconductor layer and a crystalline semiconductor pattern, respectively. The crystalline semiconductor pattern and the barrier pattern constitute an active pattern. The sacrificial crystalline semiconductor layer is removed.

The present invention is directed to methods to produce, process, and exploit nanomaterials, and particularly elongated nanowire materials. The invention provides a method for producing nanowires that includes providing a thin film of a catalyst material with varying thickness on a substrate, heating the substrate and thin film, such that the thin film disassociates at the relatively thinner regions and vapor depositing a semiconductor onto the substrate to produce nanowires. A method is also provided in which two or more thin films of different materials are overlayed over a substrate, selectively etching the first underlying thin film to create a plurality of islands of the second thin film that mask portions of the first thin film and expose other portions and growing nanowires on the first thin film. Additional methods for producing nanowires are provided.

Substrates having modified effective thermal conductivity for use in the sequential lateral solidification process are disclosed. In one arrangement, a substrate includes a glass base layer, a low conductivity layer formed adjacent to a surface of the base layer, a high conductivity layer formed adjacent to the low conductivity layer, a silicon compound layer formed adjacent to the high conductivity layer, and a silicon layer formed on the silicon compound layer. In an alternative arrangement, the substrate includes an internal subsurface melting layer which will act as a heat reservoir during subsequent sequential lateral solidification processing.

While a silicon substrate is heated, gold is evaporated thereon at a thickness of 0.6 nm, whereby melted alloy droplets are formed on the substrate surface. Then, the silicon substrate is heated to 450.degree.-650.degree. C. in a silane gas atmosphere of less than 0.5 Torr. As a result, a silane gas decomposition reaction occurs with the melted alloy droplets serving as catalysts, whereby silicon wires grow on the substrate surface. Subsequently, the metal alloy droplets at the tips of the silicon wires are removed and surface portions of the silicon wires are oxidized. Resulting surface oxide films are thereafter removed. As a result, silicon quantum wires that are thinner by the thickness of the surface oxide films are obtained.

The crystal orientations of monocrystalline semiconductor wafers may be varied by four parameters. The first parameter is the type of crystal seed used to grow the monocrystalline semiconductor ingot from which the wafers are cut. The second parameter is the angle at which the wafer is sliced from the ingot. The third parameter is the crystal plane towards which the wafer is cut. And, the fourth parameter is the position of the orientation indication feature that is used to align the wafer during processing. Different combinations of these parameters provide variations of non-standard crystal orientations of monocrystalline semiconductor wafers and semiconductor-on-insulator substrates such as silicon-on-insulator.

A method of forming an assembly of isolated nanowires of at least one material within a matrix of another material is provided. The method comprises: providing a substrate; forming a catalyst array on a major surface of the substrate; growing an array of the nanowires corresponding with the catalyst array, the nanowires, each comprising at least one material; and forming a matrix of another material that fills in spaces between the nanowires. The method is useful for producing a variety of structures useful in a number of devices, such as photonic bandgap structures and quantum dot structures.

Nano-engineered structures are disclosed, incorporating nanowhiskers of high mobility conductivity and incorporating pn junctions. In one embodiment, a nanowhisker of a first semiconducting material has a first band gap, and an enclosure comprising at least one second material with a second band gap encloses said nanoelement along at least part of its length, the second material being doped to provide opposite conductivity type charge carriers in respective first and second regions along the length of the of the nanowhisker, whereby to create in the nanowhisker by transfer of charge carriers into the nanowhisker, corresponding first and second regions of opposite conductivity type charge carriers with a region depleted of free carriers therebetween. The doping of the enclosure material may be degenerate so as to create within the nanowhisker adjacent segments having very heavy modulation doping of opposite conductivity type analogous to the heavily doped regions of an Esaki diode. In another embodiment, a nanowhisker is surrounded by polymer material containing dopant material. A step of rapid thermal annealing causes the dopant material to diffuse into the nanowhisker. In a further embodiment, a nanowhisker has a heterojunction between two different intrinsic materials, and Fermi level pinning creates a pn junction at the interface without doping.

A polymeric linking agent enables the manufacture of photovoltaic cells on flexible substrates, including, for example, polymeric substrates. Photovoltaic cells may be fabricated by a relatively simple continuous manufacturing process, for example, a roll-to-roll process, instead of a batch process.

According to one embodiment, a method of fabricating a nanotube on a substrate is provided. The method can include a step for attaching a catalyst to a substrate. The method can also include a step for heating the catalyst to a predetermined temperature such that a nanotube grows from the catalyst. Further, the method can include a step for directing a feeding gas over the catalyst in a predetermined direction such that the nanotube grows in the predetermined direction.

A method for large-scale manufacturing of gallium nitride includes a process for reducing and / or minimizing contamination in the crystals, for solvent addition to an autoclave, for improving or optimizing the solvent atmosphere composition, for removal of the solvent from the autoclave, and for recycling of the solvent. The method is scalable up to large volumes and is cost effective.